Method for removing particle contamination in groove after wafer CMP

The invention provides a method for removing particle contamination in a groove after wafer CMP. The method comprises the following steps that S1, a silicon dioxide thin layer is deposited on the surface of a wafer; s2, silicon dioxide outside the side wall of the wafer groove is etched through a dry etching process, and then CMP process treatment is carried out; s3, corroding the silicon dioxide in the groove of the wafer through an acidic cleaning solution, so that the large-particle contamination embedded in the groove is changed into a loose state; s4, cleaning the wafer by using a first mixed cleaning solution; s5, cleaning the wafer by using ultrasonic waves; and S6, removing small particles on the wafer through cooperation of megasonic waves and a second mixed cleaning solution. According to the method, the silicon dioxide thin layer is deposited before CMP, the particles in the groove are loosened by corroding silicon dioxide after CMP, and the problem that particle contamination generated after the w